Background: Population-based screening programs for suicidal ideation (SI) are becoming standard practice. This year, VHA is implementing a new multi-stage SI screening and evaluation process, VA Risk-ID. However, prior research has shown that Veterans often feel uncomfortable disclosing SI during screening, and that Veterans frequently do not disclose SI at healthcare visits proximal to suicide. Further, there is almost nothing known about how SI screening experiences may impact subsequent treatment engagement. Factors known to be associated with treatment engagement include effective patient-clinician communication, therapeutic alliance, and collaborative treatment planning. Negative perceptions of SI screening have the potential to adversely affect Veteran comfort disclosing and discussing SI, as well as subsequent engagement in care. Significance/Impact: Suicide prevention is VHA?s highest priority, and optimizing engagement of at-risk Veterans in treatment is of critical importance. This project addresses key gaps: 1) It will generate knowledge about both positive and potentially negative impacts of a population-based SI screening process; 2) It will generate comprehensive information about SI screening from the perspective of patients; and 3) It will examine the relationship between screening experiences and subsequent engagement in care. Innovation: This project will use a mixed methods approach to characterize the ?natural history? of the treatment of Veterans screened for SI in primary care and mental health settings primarily from the perspective of Veterans, from the point of initial depression or PTSD screening until 6 months after screening. Specific Aims: (1) In a national, stratified random sample of Veterans screened in primary care and mental health, using quantitative surveys, characterize Veteran experiences with VA Risk-ID screening and clinical evaluation that takes place in response to screening; (2) Conduct semi-structured qualitative interviews with Veterans and staff who participate in SI screening, with the goal of identifying ways to improve screening and engagement after screening; (3) Among the group of Veterans screened in primary care, examine the extent to which screening process variables are associated with mental health treatment utilization over 6 months. Methodology: This 3-year mixed-methods project will utilize quantitative and qualitative data from a national, stratified random sample of Veterans. In Aim 1, we will mail recruitment letters immediately after VA Risk-ID screening to 2,000 Veterans screened in primary care and 2,000 Veterans screened in specialty mental health who have not received mental health treatment in the prior 12 months. Respondents will be invited to complete surveys including measures assessing satisfaction with screening, patient-care team interactions and perceived barriers to care and disclosure. In Aim 2, informed by Aim 1 survey results, up to approximately 40 Veterans identified from the survey cohorts will participate in semi-structured interviews. We will also interview up to 40 clinical staff members from primary care and mental health settings of three or more VHA facilities. Qualitative analyses will prioritize identification of ways for clinical teams to detect and respond to SI more satisfactorily and effectively. In Aim 3, within the group of Veterans screened in primary care, we will examine the extent to which screening results and survey variables are associated with subsequent engagement in mental health treatment over 6 months. Outcomes will include specialty mental health visits attended (when referred) and antidepressant fills (when recommended by providers). VHA?s Corporate Data Warehouse will provide care utilization data. Multivariable models will adjust for patient and care team and site characteristics. Next Steps/Implementation: This project will inform further development and implementation of VHA?s SI screening processes, and lay groundwork for 1) development and testing of new interventions for primary care and mental health care teams to improve SI screening and care engagement; and 2) additional research examining the impacts of early care experiences of Veterans at risk for suicide on health outcomes.